The best nature writing from the newspaper, magazine, blog and book authors of the Lone Star State . . .

Sunday, January 13, 2008

Buff-bellied Hummingbird, Our Wintertime Hummer by Ro Wauer

Buff-bellied hummingbirds are our only year-round resident hummers. A few other hummingbird species occur at various other times, ruby-throated and black-chinned hummers in summer and a few other species pass through South Texas during migration, and occasionally some of these, such as the rufous hummingbirds, overwinter at choice areas where they can find an adequate supply of food. But the buff-bellied is our only full-time resident hummingbird.

At four and a half inches long, the buff-bellied hummingbird is the largest hummer occurring regularly in the eastern half of Texas, compared with three and a half inches for both the ruby-throats and black-chins. The buff-belly is our only species with a red bill, emerald green throat, buff underparts, and a rufous tail. Buff-bellies also possess a unique voice, producing high-pitched metallic or shrill, squeaky notes. Some of these can be loud and piercing, especially during courtship or when a bird is defending a territory. Although the sexes are marked alike, adult males are somewhat brighter with a redder bill.

Buff-bellies have a bold and assertive personality. Males often perch in a live oak within easy viewing of a feeder or patch of flowering plants. They may sit for long periods, watching whatever is moving in their surroundings, and then suddenly, without warning, they will streak off to another perch or after another hummingbird, a territorial invader. Or they may dive down to sip liquid from a feeder or flower, and then return to a favorite perch.

Buff-bellied hummingbirds are tropical hummers that range as far south as Guatemala but only as far north as South Texas and the southern edge of the Central Texas plains during their breeding season. But this has not always been the case. Only since the 1970s have they been recorded regularly north of the Lower Rio Grande Valley. By the early 1990s they had moved northward into Victoria County for the summer months, and since the late 1990s have become a fulltime resident.

Preferred habitat always includes oaks, although nesting can occur on a variety of other trees and shrubs. In fall 1995, I discovered a deserted buff-belly nest on a hanging yaupon branch. Like all hummingbird nests, this one was constructed of plant fibers and decorated with lichens and bound with spider webbing. New hummingbird nests are little more than thimble-size structures, but by the time the young are fledged the nests usually have been stretched to twice the original size.

Buff-bellies were earlier known as fawn-breasted or Yucatan hummingbirds, the latter name in recognition of their type locality. And their scientific name is Amazilia yucatanensis. But none of these names does justice to these birds, which are among our most colorful and personable hummers.

Naturalist Louis J. Halle also had a deep appreciation of hummingbirds. He wrote: “I have always felt that the hummingbird was a special gift to the New World…The human imagination, which has created unicorn, dragon, and phoenix, has created nothing more wondrous. It is like a precious gem, emerald or ruby, that has life and movement, that hovers, dips, and darts in the air. Looking only at its form and color, its jeweled surface, one would say it belongs in a prince’s turban. Its wings have more delicacy than the finest watchwork, humming when they are set off, whirring so fast they are blurred to sight, shooting it here and there, back and forth, or holding it stationary in the air.”